Conventionally, track-supporting rollers made of steel are used to support the upper crawler section of a crawler track in a crawler chassis. The crawler track chain links roll directly on the steel rollers, which may lead to an undesired noise development at the workplace. In addition, it has shown that the metal-on-metal contact between the chain links and the steel rollers results in a greater wear not only of the steel rollers, but also of the chain links of the crawler track. Remedying such signs of wear is very expensive, and cannot be done right at the construction site, but has to be carried out in a workshop. Also, rust deposits may be formed between the steel rollers and the chain links if the construction machine with the crawler chassis remains outdoors on the construction site for a longer period. Above all, this may lead to split-offs on the steel roller surface when the construction machine starts moving, resulting in an unsteady and noisy run of the crawler track.
EP 1 666 345 B1 discloses a crawler chassis having a track-supporting roller assembly which is positioned next to a drive wheel. The track-supporting roller assembly comprises a supporting roller which is mounted on both sides and on which the crawler track rolls along. The supporting roller has an increased diameter at its outer ends, on which position the chain links are supported.
US 2010/0096196 A1 discloses another crawler chassis. The crawler chassis comprises several track-supporting rollers which are arranged on a carrier, respectively mounted on both sides, between a drive wheel and a return wheel. The supporting surface for the chain links is formed by outer portions of the respective track-supporting rollers that have an increased diameter. The respective track-supporting rollers are mounted in a lubricating bushing on both sides. It is difficult, however, to seal the lubricating bushing bearing in such a way that an escape of lubricant from the bearing during the operation is prevented, which could result in an unsteady run of the respective track-supporting rollers.
EP 1 798 138 B1 discloses a mounting structure for a track-supporting roller for a crawler track which is mounted on a lower frame of the crawler chassis. The mounting structure comprises a mounting part and a support part for the carrier roller. The support part comprises a clamping closure which can be screwed such that a shaft of the carrier roller can be mounted in the clamping closure, on which shaft the carrier roller is rotatably fixed. The drawback of this arrangement is that the screw closure can become loose when vibrations occur during the operation, so that the carrier roller may slip out of the support part.